Plants: They Do Call It Garden Trains -- Right?
The most important thing to consider when selecting your plants is the time it will take to maintain them. The more interested you are in the "garden" part of Garden Trains, the more likely you will be willing to invest in their upkeep on the railroad.
You need to consider that fast growing plants can easily over grow your track and planting to close too the track can cause some unexpected derailrments as the branches extend into the right-of-way of your running trains.
When starting out building a garden railroad a builder is usually most concerned about getting track down, acquiring rolling stock and buildings. If a layout is not being built in an established garden where the builder is trying to include existing plants, a new builder often overlooks being particular about the plants he/she purchases. Hence people often take the easy way out and pick up inexpensive plants like Dwarf Alberta Spruce or Boxwoods at the local Lowe's or Home Depot.
If you do decide to take the approach of using less expensive and common plants initially, one thing that can help is keeping the plants in the pots when you plant them. It will slow the growth a little and it will make them easier to dig out when/if you decide to replace them later on. By the time the plants mature to the point they are too large you may be ready to replace them with more "scale" plants.
A beautiful Garden Railroad owes its success to many types of care and considerations. Chief among them is a keen assessment and understanding of the particular conditions of the landscape site. No matter how attractive and healthy when chosen, or how well-tended once in the ground, if the plant is not suited to the site it may be a serious disappointment.
When choosing plants for your railroadscape, it is important to consider the following factors: the planting site's climate and micro-climates; the amounts of direct and indirect sunlight received throughout the day; exposure to wind and, in coastal areas, salt; various characteristics of the soil and the underground environment.
Trees provide verticality in a scene. They can be used individually as landmarks or focal points, in groves to accent a larger area, or in forests to cover a mountainside. When choosing trees, try to find those that have scale-sized components. A larger tree with tiny needles or leaves will read better in the railway setting than a smaller tree with big leaves.
Certain mosses can make convincing lawns, and groundcovers can become open meadows. Upright thymes can form shrubbery and miniature hedges.
Plant material near the track can seriously affect the look of the railway. A full-size railway recedes into the landscape when viewed from afar. However, when seen close up, you realize the plants are kept at bay. A poorly maintained line might have plants encroaching while a well maintained one will have a sharp delineation between plant and railroad.